This invention relates to archery bows, and more particularly to an archery bow characterized by requiring less pull force at full draw than at an intermediate draw position.
Archery bows of the class described, and commonly referred to as compound bows, have been provided heretofore. Their principal advantage lies in the reduced pull force required at full draw, whereby an archer may utilize a pull force greater than his normal capabilities, while simultaneously affording greater sighting control.
In order further to increase the mechanical advantage and to accommodate adjustment of the drop over point of compound bows, they have been provided with cam members, mounted at each extremity of the limbs, having diametrically different paired cam elements. However, the compound bows provided heretofore with paired cam elements have had their cam elements concentrically joined together. While increasing the force differential between the full draw and intermediate peak draw positions, compared to that of other compound bows, the use of concentric cam elements has been accompanied by certain other disadvantages.
In the prior art compound bows of this class the point of full draw is achieved at a relatively large draw distance. This limits the usefulness of the bows or even prevents their use by persons having short arms.
In addition the time interval between release at full draw and the point when intermediate peak draw is reached, is too short, imparting an excessively large acceleration force on the arrow. This causes loss of arrow stability and may at times even cause its collapse.
Furthermore, the drop over point at full draw is too closely defined on the prior art bows, requiring accurate indexing means to assure that a proper draw is maintained up to the moment of release.